I have a set of almost new 2009 sti front struts (600miles). These were taken off an sti at 600miles because the car was turned into a racecar. I got them and performed the modifications to allow them to bolt up to the 5x100 knuckle. these are the inverted dampers made by KYB and they have been dissasembled during welding and reassembled with fresh grease in the lowers.

I believe they will work on any impreza or wrx from 02-07. not totally sure on the years of compatibility but I know they will not work properly on 08 (too much positive camber due to the length of the mounting tabs). It appears that the 08 uses much shorter lower mounting tabs than other years.